Ser Barristan describes an infatuation of Rhaella’s from her youth, a knight of the stormlands:

“He put away his lance the day your lady mother wed your father. Afterward he became most pious, and was heard to say that only the Maiden could replace Queen Rhaella in his heart. His passion was impossible, of course. A landed knight is no fit consort for a princess of royal blood.”

It seems clear that this landed knight from the stormlands, a jouster skilled enough to win a tourney with a princess in attendance, who put away his lance and became very pious, is none other than Ser Bonifer Hasty, called Bonifer the Good. Jaime reflects in A Feast for Crows that:

Ser Bonifer himself had been a promising knight in his youth, but something had happened to him, a defeat or a disgrace or a near brush with death, and afterward he had decided that jousting was an empty vanity and put away his lance for good and all.